SAN FRANCISCO — Apple Computer Inc. completed its switch to Intel Corp. microprocessors and previewed its next-generation operating system Monday, shifting attention — for the moment — from the company's troubles surrounding the mishandling of stock options.

CEO Steve Jobs, speaking to thousands of engineers at the company's Worldwide Developer Conference, showed off Intel-based Macs for professional users and servers for businesses. They replace the last Apple machines to run PowerPC chips built by IBM Corp. and Freescale Semiconductor Inc.

Jobs also previewed the upcoming Mac OS X release, dubbed "Leopard," taking a few swipes at rival Microsoft Corp. and its much-delayed Windows Vista operating system. Since Windows XP was launched in 2001, Apple has released five major updates to Mac OS X. Leopard is expected in spring 2007.

"Our friends in Redmond, they spend over $5 billion in R&D, but these days they just try to copy Google and Apple," Jobs said. "So I guess it's a good example of how money isn't everything."

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Jobs did not mention the stock option scandal now hanging over the Cupertino, Calif.-based maker of Macs and iPod music players. Last week, Apple said it might have to restate financial results as far back as September 2002 as a probe into its granting of stock options widens.

Details of how some other company executives were granted options right before the stock prices rose during the period under investigation — between 1997 and 2001 — were outlined Monday in The Wall Street Journal. Apple spokesman Steve Dowling declined to comment on the report, saying the company will not be making any further statements until its internal investigation is completed.

Apple stock lost $1.09, or 1.6 percent, to close at $67.21 in Monday trading on the Nasdaq Stock Market.

The new "Mac Pro" computer, available immediately, replaces the PowerMac G5. The new system, which runs the latest Intel Xeon chip, is two times faster and costs $2,499 — about $800 less than the G5, Jobs said.

The new Xserve computers, which also run Xeon chips, will be available in October. They are five times more powerful, depending on the applications in use, and will cost $2,999, the company said.

Earlier this year, Apple launched Intel-based iMacs and notebook computers. In January, Jobs said the process would be completed by the end of the year. In fact, the entire product line made the switch within 210 days, he said Monday.

The products come as Apple says it is making progress in gaining new Macintosh customers — more than 50 percent of Mac buyers from Apple's retail stores last quarter were new to the platform, Jobs said.

Many analysts expect the entire lineup of Macs, which use the same chips as its Windows-based PC rivals, will boost Apple's overall computer market share in the United States. For years, it has been less than 5 percent.